Abstract
Introduction
So if you find nothing in the corridors open the doors, and if you find nothing behind these doors there are more floors. Kafka (n.d.: 284–285)
In Franz Kafka’s short story ‘The Advocates’, the reader is led into an endless maze-like world of corridors in which the protagonist is constantly searching for someone to legally represent them for some unspecified reason. However, instead of finding the search for an advocate to be a straightforward process, much like the corridors in which the ongoing search continues, the nameless protagonist is drawn into an endless and repetitive search through labyrinth-like pathways that are unnavigable. The more one moves forward, the more ‘narrow and austerely vaulted’ the unfolding corridors, ‘turn[ing] in gradual curves with high, sparsely decorated doors’. At stake in this representation of corridors are the ways in which such passages, particularly their function and spatial and temporal linearity, are problematised and put into question. Contrary to the idea that a corridor, at its very simplest, is constituted of a straight forward passageway that connects two distinct points, the imagined corridors that we find in Kafka’s story point to an arrangement of situations, materialities and people where different activities entangle and co-shape each other. While the function of corridors here seems, at first, to be connected with finding an advocate because ‘he is needed everywhere’, in the end we are lured into a process where interrupting one’s movement can lead to a catastrophe. Hence, seen this way, the very functionality of these passages seems to be
Kafka’s story is useful to us because it offers an interpretation to problematise two critical ideas associated with corridors: first, the notion that corridors are linear passages that connect different sites; and second, that they are interdependent systems of circulation with a singular objective to facilitate mobility. Such representations of corridors depict them as designed to move things across space and territory, whether goods, people, information flows or natural resources. Consider for instance the ways in which over the last decade, the term ‘corridor’ has become ever-present in urban studies and the worlds of planning, governance, investment and geopolitics. Corridors in the contemporary era have been made visible through the Chinese Belt and Road Initiative (BRI) 1 and other programmes such as the European Union’s Global Gateway and the US-led Partnership for Global Infrastructure and Investment. What the above investments share is a geographical and imaginary depiction of corridors as an uninterrupted line connecting disparate spaces into a unitary whole. And yet, as the corridors in Kafka’s short story suggest, they require textured understandings given the contradictions and complexities playing out as these initiatives are planned, constructed and operationalised. Contrary to those approaches, our rethinking of corridors understands them as constituted by a differential arrangement of things, people, flows and temporalities in ways that problematise the apparent underlying logic of the corridor as a linear device. Corridors take multiple different forms and functions and involve complex arrangements and relations of financing, operations and construction, user experiences and implications for surrounding urban spaces and populations, even as they share an intimate connection to new forms of infrastructure investment and broader processes of time–space compression (Harvey, 1990). As Mayer and Zhang (2021: 988) argue, ‘Today, the rise of corridors is at the heart of a process of spatial restructuring and geographical reimagining’. However, given this growing use of the term to describe an array of different spatial, planning and infrastructure initiatives across multiple histories and geographies, there remains limited work that has reflected upon its (historical) emergence and attempts to think through debates, understandings and logics surrounding and suffusing this term. What is of interest to us here, apart from the various meanings, functions and imaginations entailed in the term corridor, is its analytical importance for urban (and regional) space and urban studies more generally.
At the same time, in spatial disciplines such as planning, the term has become especially prominent through mirroring trends in urban and regional policy. The term corridor has arguably become shorthand for an ever-growing, myriad set of routes across land and ocean that cut across regions and territories, countries and cities. As we show, however, there is an earlier history of the corridor denoting an internal passageway or form of architecture (Jarzombek, 2010). However, the origins of its meaning, as something more extensive that facilitates various kinds of movements, are distinct and geographically diffuse. The question then arises as to what extent these growing multiple uses of the term corridor reflect a broader change in how space, urbanities and, by extension, urban life are being approached, conceptualised and articulated. In this article, we set out to respond to this imperative through an examination of this term, developing a critical reflection on its histories, contemporary usage and empirical and conceptual implications for urban studies.
By developing a short genealogy, we first demonstrate that the history of the term is one of variegated usage within the context of geographically diverse planning regimes and more broadly in the social sciences. Secondly, given the fragmentary, non-linear nature of the development of the term, we turn our attention to interrogating its contemporary usage. We develop a loose typology of 10 distinct but often overlapping ideas of the corridor to articulate more precisely its use in urban studies: (i) infrastructure, (ii) economic, growth and development (EGD), (iii) transit, (iv) urban, (v) maritime, (vi) agricultural, (vii) conservation, (xiii) peopled, (ix) illicit and (x) remittance. We track the emergence of each type of corridor and examine its functional and governance characteristics, demonstrating how meanings often remain fuzzy and interchangeable. Tracing the goals and key components of these different corridor types reveals that such overlaps are key to the way in which corridor, as a concept, is mobilised today. For instance, most corridor projects, designed and implemented by planning regimes, encompass and bring together diverse infrastructural investments driven by issues of accelerating circulation and flow. Corridors, then, are usually identified and categorised on the basis of a specific aim, strategy or functionality. Other corridors emerge as people engage and navigate actual terrain and organise their socio-economic activities in response to and sometimes in contravention of official interventions.
Our aim is to extend an understanding of the importance of corridors in urban studies and beyond, both as existing initiatives transforming urban space and in the analytical possibilities and foreclosures accompanying their use as a term. We do so by synthesising the key concerns from our typology to produce four
What’s in a term? Corridor genealogies in urban studies
In Luckhurst’s (2019: 17) history
The term jumps from this internal spatial designation much later, finding resonance in various (and increasing) kinds of urban and regional planning models, discourses and approaches. These have overlapping histories, meanings and uses that show how planners have comprehended and utilised the corridor across time and space. First, there is a long history of corridor models closely aligned with various European spatial planning traditions in the late 19th and early 20th centuries. These are bounded within existing cities or as propositions for new urban extensions rather than as infrastructural connections facilitating urban-regional growth. The most prominent of these is the Ciudad Lineal in Madrid, built in the 1890s from the linearism of Arturo Y Mata, who, according to Collins (1959: 38), was the: first of a series of planners who have relinquished the conventional city nucleus for an extended type of region plan which assumes that surface transportation is such a basic organisational factor in modern living that we must arrange ourselves and our activities along its routes.
Ciudad Lineal was interpreted by the Greek architect and author of ‘On linear cities’Doxiadis (1967: 35) as a ‘small-scale corridor-like expansion of cities’, emphasising that for much of the 20th century the corridor within Europe was associated with the growth of new neighbourhoods out of existing cities along new transit routes. For Priemus and Zonneveld (2003: 168), in their landmark study, this linear planning tradition impacted spatial development approaches, as many ‘regional plans made since have advocated some sort of linear extension of large cities based upon infrastructure’. Various studies have explored the linear initiatives that stemmed out of Y Mata’s work, from the first Russian
Second, in a separate set of developments in the 1990s, the use of the term shifted in scale from urban extensions into regional extended initiatives, as it was taken up in Dutch national planning regimes (Van Duinen, 2013; Verkennis, 1999). This new model represented a shift in scale from previous planning visions, moving from the city to the (urbanised) region. This tradition of planning-orientated work has been well documented from the 1990s, with a range of competing ideas of how a corridor functions and its purpose in relation to ‘axes’ of infrastructure, economic development and urbanisation. The more recent emergence of the term EuroCorridor was highly connected to this earlier Dutch practice, with studies arguing for the use of the urban-regional corridor as critical to the economic and geopolitical integration of an expanding European Union (Grčić and Ratkaj, 2003). As Witte et al. (2014: 40) argued, the rationale was concerned with ‘enhancing the level of connectivity’, which ‘would stimulate the economic performance of lagging regions’. This policy objective was configured to incorporate peripheral southern and eastern cities into the European Union. Subsequent development of the TEN-T network, currently spanning nine transnational transit corridors, is the latest iteration of these attempts to integrate Europe (Goldmann and Wessel, 2020).
Third, much of the scholarship on the emergence of this planning concept has had a Western-centric viewpoint. For instance, according to Priemus and Zonneveld (2003), the EuroCorridor model was later exported worldwide. Nevertheless, related literature has explored corridors beyond Europe. This is closely related to the modernisation paradigms that pervaded spatial planning regimes in the global South from the 1950s, especially through the idea of the economic corridor as critical to development and lasting until the shift to neoliberalism and structural adjustment policies in the late 1970s. Projects included, for instance, the Tazara Railway between the Zambian Copperbelt and Dar es Salaam. These corridors can also be connected to longer histories of colonialism. As the imperialist Sir Eliot (1966: 208) noted on Kenya and the ‘Lunatic Express’, ‘It is not an uncommon thing for a line to open up a country, but this line literally created a country’. 2 Much scholarship focuses on the geographies, politics and technologies that produced what Del Testa (1999) termed ‘imperial corridors’. These corridors were deployed as part of extractive geographies between imperial centres and hinterlands. Some of this work highlights the close relations between new deployments of regional infrastructures like railways and intensifying urbanisation patterns. For instance, Sahoo (2020) connects the growth of the British colonial railway to the emergence of urban corridors in the form of developing towns and cities due to their role in these logistical geographies. However, despite notable similarities, very little of this significant body of scholarship on colonial infrastructures and networks explicitly uses the term corridor.
Fourth, studies focus on the proliferation of the corridor as a spatial product emerging from Chinese planning models and later exported beyond the country’s borders, particularly through the rise of development corridors in sub-Saharan Africa (Harrison and Todes, 1996). The history of the corridor in these planning regimes is traced to the late 1970s and the creation of new zones and territories to link Chinese economic activity to world trade (Mayer and Zhang, 2021), such as the Shenzhen Special Economic Zone. Other interpretations place the evolution of the corridor in China to the state-led model of urbanisation in the late 1990s (Zhu, 1999), with Smith (2022: 3) contending that this was later intensified and shifted beyond China’s borders as the city of ‘Chongqing pursued urbanisation by building infrastructural linkages to the Eurasian continent and repositioning itself as an emerging global city’. The rise of the BRI in the post-2008 period is understood as a critical moment in the export of this model, even as some scholars trace the contemporary emergence of the corridor model elsewhere in Asia (Xu et al., 2021). In this understanding, the corridor has become the primary means of implementing Chinese geo-political and economic ambitions to connect with adjacent territories and reconfigure territories further afield (Derudder et al., 2018).
Finally, with these various overlapping urban planning regimes from the 1960s, new conceptions of corridor development began to emerge from urban studies (as opposed to the planning models we have documented above) as an alternative explanation for the growth pattern and relations between urban settlements. Foremost amongst these was the work of Whebell (1969), who, as Xu et al. (2021) argued, ‘carried out systematic research on the corridor for the first time’. In particular, Whebell’s paper ‘Corridors: A theory of urban systems’ was an original intervention into debates about urban-regional growth. Whebell proposed an alternative explanatory framework to that of Central Place Theory (CPT) developed by Christaller (1966 [1933]) (and later Lösch, 1938) in which urban settlements form a regional hierarchy through which urban-regional growth proceeds as a naturalised process. Critiquing this tradition, Whebell (1969: 4) found, through research in southern Ontario, a region with ‘a severe distortion of the Christaller–Lösch landscape’. He proposed instead that urbanisation was proceeding along a corridor as ‘a linear pattern of major towns joined by highly developed “bundles” of transport routes’ (Whebell, 1969: 4). The idea of linear growth along regional and continental infrastructure and across diverse territories (rather than the homogeneous, flat space of CPT) differs significantly from the prevailing urban theory of the time.
The non-linear and fragmentary set of origins, uses and geographical meanings of the corridor term across various planning regimes further complicates its current analytical usage in urban studies and beyond. Additionally, this lack of a singular meaning in these different histories makes it imperative to rethink the multiple and potentially contradictory ways this term is deployed today, so as to shed further light on its growing prevalence, and to ask what the term offers to contemporary urban studies. Such an attempt corresponds to the analytical need to make sense of how the material and immaterial dynamics of corridors have been (re-)employed to promote anew and reaffirm the development logic of unending circulation and continuous connectivity.
Towards a corridor typology
Despite or maybe because of the multiple histories and interpretations we set out, the term corridor in urban studies remains necessarily open and broad. As such, its usage highlights the ambivalences and contestation permeating the term. Following these threads further requires identifying the different types of corridors visible in scholarship. In doing so, we demonstrate how this contested, slippery term is used in myriad ways. While not seeking to close down or exclude other meanings, we propose an initial corridor ‘typology’ from a critical review.
Infrastructure corridor
Infrastructure corridors have been approached as material and immaterial arrangements associated with processes of standardisation and infrastructure-led development in order to enable long-distance seamless interconnectivity and circulation within and across various territories as a way to deliver different services (Carse and Lewis, 2017; Easterling, 2014; Schindler and Kanai, 2021; Thorn et al., 2022; see also Larkin, 2013). Newhouse and Simone (2017) conceptualise infrastructure corridors as an arrangement always in motion and as creating new movements. Typically, infrastructure corridors are not limited to transport infrastructure but can also include investments in manufacturing and processing capacities to boost the level and type of goods and services moving along the corridor route (e.g. industrial parks and special economic zones). These corridors are thus critical in facilitating and shaping (certain kinds of) movement and mobility across different scales, contexts and spaces.
Such approaches can also be identified in the definition of corridors provided by Priemus and Zonneveld (2003: 167), which they understand as ‘[b]undles of infrastructure that link two or more urban areas’. For them, corridors are constituted by an array of infrastructures that ‘work’ together towards the effective facilitation of seamless circulation across a particular route. By looking at the corridor as an infrastructure axis, they highlight interconnectivity, multimodality and interdependency as factors of corridor operation and work (Priemus and Zonneveld, 2003: 173). This is related to a constant process of standardisation, coherence and translation. As Grappi (2018: 181) explains, corridors are always situated ‘between the existing and the new’ since they seem to put forward a process of translation entailing the shifting of various ‘operations and assemblages into new frameworks’. Instead of approaching corridors as homogeneous, scholars have been highlighting their heterogeneous, malleable dynamics, which constantly challenge their form and function (Grappi, 2018; Wiig and Silver, 2019). Similarly, in their attempts to conceptualise ‘geographically-specific, infrastructurally-dense spaces’ through the notion of ‘power corridors’, Murton and Lord (2020: 2) do not see them as monolithic but rather as ‘co-constructed by an array of differently positioned actors’. In connecting different material and soft infrastructures to serve a variety of economic and political ends, infrastructure corridors constitute the very ‘fabric of contemporary capitalism’ (Grappi, 2018: 180).
Economic, growth and development corridors
Corridors have also been approached as financial devices through which growth, prosperity and national development plans can be achieved (Xu et al., 2021), reflecting the current gradual shift from zoning technologies to economic corridors as the latest wave of logistical operations to foster economic growth in contemporary capitalism. For Enns and Bersaglio (2020: 106), such processes are reflected in the economic corridor’s primary functions: first, ‘to facilitate movement and logistics along the transport corridor, [and second] to support the growth of existing and establishment of new value-added industries’. Thorn et al. (2022: 1) similarly argue that ‘infrastructure corridors become development corridors when larger, often transnational, and linear, geographical areas are targeted for domestic and international investment’. Such an approach is closely related to Priemus and Zonneveld’s (2003) idea that corridors function along an economic development axis. For them, ‘a corridor is neither a sectoral nor a spatial concept, but rather the indication of a challenge: that of improving the governance of infrastructure and area development’ (Priemus and Zonneveld, 2003: 176).
Seen from this point of view, EGD corridors represent attempts to secure investment and operate primarily through financial logics. As such, through constant attempts to ‘get the territory right’, they facilitate ways in which particular places, ‘like resource frontiers and subnational urban systems’, can be plugged into transnational networks of production and trade (Schindler and Kanai, 2021: 40). Such corridors are also strongly associated with the concentration of localities and disparate programmes (Dannenberg et al., 2018; Harrison and Todes, 1996) over which they ‘assert spatial coherence and centrality of capital as social power’ (Lesutis, 2020: 603). By linking separate projects – including energy and extractivist activities – and by providing ‘a spatial framework for establishing an integrated development programme’ (Harrison and Todes, 1996: 72), such mega-projects spatialise and (re)design territories (Enns and Bersaglio, 2020; Scholvin, 2021; see also Chome et al., 2020; Lesutis, 2020). Thus, EGD corridors cannot be examined in isolation but rather ‘have to be analyzed as part of integrated economic networks, such as regional and value chains and production networks’ (Brunner, 2013, cited in Grappi, 2018: 179).
Scholars have also problematised the relationship between economic activity and the built environment in the functioning of corridors. Advocating for a path dependency approach, Priemus and Zonneveld (2003: 173; see also Whebell, 1969) consider economic activities to follow infrastructure development and planning. For them, ‘the spatial results of functional economic activities are strongly determined by the infrastructure network’ (Priemus and Zonneveld, 2003: 173). Rippa (2020: 63) also explains that economic corridors are ‘conduits of exchange’ that reconfigure particular spaces through financial logics, and thus have a critical effect on the everyday grammar of urban life. For Dey and Grappi (2015: 154), ‘the birth of the corridor economy lies in the various spatial techniques that have been used to segregate economic spaces’.
EGD corridors engender ‘economies of anticipation’ (Chome et al., 2020: 300), which are tied to future aspirations and expectations towards ‘desirable futures’ (Müller-Mahn, 2020: 156; see also Anand, 2017; Grappi, 2018; Harvey and Knox, 2015). At stake here are the specific material, symbolic and discursive dynamics of ‘development’ and their implications for different actors. Lesutis (2020: 604), for instance, indicates that the particular modern aesthetic associated with imaginaries of futurity ‘demonstrates that the development corridor logic … normatively underpins what is “development”’ (see also Harrison and Todes, 1996). There is also a strong association between developmental logics and corridorisation borne out of the historically top-down approach of such projects. Development corridors embody concrete ideological projects that feed from, accentuate and affirm colonial developmental logics (Aalders et al., 2021; Enns and Bersaglio, 2020). In other cases, they draw on old trading routes (Rippa, 2020). However, in transforming the technological and material features of those routes (see McCartney, 2022), EGD corridors may erase previously established routes through attempts to project conceptions of newness and innovation. By introducing new regulations and modes of securitisation, they cut off local populations, small-scale traders and hinterlands which used to benefit from cross-border pathways (Rippa, 2020). As such, they have the capacity to enact state-making and legitimation processes (Grappi, 2018) that extend ‘the reach and control of the state’ and reinforce ‘state territoriality’ (Zajontz, 2024: 5). Nevertheless, these processes are fragmented, as they emerge through complex interactions between a range of state and private actors (Lesutis, 2020).
Transit corridors
Transit or transport corridors are understood as connections constituted through different transport modes that enable both passenger and freight traffic, with the overall aim of boosting economic activity (Priemus and Zonneveld, 2003). They usually include a combination of road, railway, information and communication technology infrastructure, electric lines, waterways and airports. Transit corridors dedicated to passenger traffic usually take the form of urban corridors connecting a series of cities and towns. During 2009–2013, the transit corridor model rose to prominence in the formation of economic and development corridors as planners and scholars realised the importance of traffic accessibility to different geographical areas (Xu et al., 2021). Trade-focused transit corridors have assumed importance in regional integration as a means of diversifying markets and maintaining trade-led growth. Within this context, sections of larger economic and development corridors have been planned and developed as transit corridors to facilitate trade and reduce transport costs. Transit corridors are paramount for landlocked countries requiring access to ports in neighbouring states since they enable the capacity to exercise control over freight and to deal directly with importers and exporters, thereby reducing transactional costs (UN-Habitat, 2015).
The globalised nature of supply chain demands created a requirement for coordination of intercontinental transportation, long-distance land transit, as well as local goods delivery (Makarova et al., 2020). The widespread application of principles of modularisation, standardisation, mechanisation and automation in the post-war period has transformed trade transit corridors (Klose, 2015). Transit corridors geared towards trade require material coordination between multiple modes of transport, as well as governance regimes in order to minimise transportation costs. Within this context, the emergence of the container for shipment, in particular, revolutionised intermodal transportation (Rodrigue and Notteboom, 2009; see also Cowen, 2014). Multi-modality became popular following the deregulation wave in the late 1970s in the USA since it incentivised joint planning and cooperation and the proliferation of intermediaries (Cowen, 2014). The maritime sector adopted the container after standardising the box and its infrastructure, followed by the railways (Cowen, 2014). Rodrigue and Notteboom (2009: 4) note that such a seamless system meant that ‘customers could purchase the service to ship their products from door to door without having to concern themselves with modal barriers’. Furthermore, clients could obtain one through rate from the departure point to the destination despite goods being transferred from one mode to another (Rodrigue and Notteboom, 2009).
Logistics corridors
A logistics corridor can be understood as distinct from a transit corridor, one that is specifically dedicated to the passage of goods and raw materials, with the added capacities of processing, packaging and value addition before goods are shipped off to markets. While supply chain refers to the processes of logistics, corridors refer to both the materiality of hard infrastructure required (e.g. roads, logistics centres) and the soft infrastructure of governance (e.g. policy standardisation, establishment of protocols) (Grappi, 2018). In addition to multiple modes of transport, logistics corridors also involve different types of (urban) nodes, including cities, ports and logistics centres.
Logistics corridors aim to enable frictionless movement of goods and capital to markets, and in the process promise to ‘uplift’ all participating countries (Grappi, 2018). In this respect, logistics corridors share common features with EGD corridors, although the latter also focus specifically on production and manufacturing. It is not, therefore, incidental that logistics corridors have emerged in tandem with globalised supply chains. As the factory became disaggregated, manufacturing, value addition and packaging proceeded across a series of logistic spaces requiring secure, seamless transport. Cowen (2014) argues that instead of distinguishing sharply between manufacturing, transport and logistics, all three should be considered as part of production. This more expansive understanding of logistics corridors then overlaps with studies of economic corridors.
The establishment of logistics corridors involves coordination of a range of institutional actors and hierarchies across scales and contexts (Kunaka and Carruthers, 2014). In addition to the standardisation of policies, the multimodal nature of logistics corridors requires technical alignment and smooth interfacing to reduce transfer costs and optimise transit times. Finally, a critical aspect of logistics corridor governance is concerned with the contemporary rise of supply chain security. While in the past, supply chain security centred primarily on the protection of cargo from physical threats, such as theft, natural disasters and terrorism, today cyber threats to information technologies associated with the chain in the form of malware attacks, piracy, unauthorised access to software and data are a key priority (Cowen, 2014). Cowen (2010, 2014) also points out that as the financial interests of private corporations are increasingly securitised, supply chain security has also expanded to include protection against bureaucratic and national security policies as well as labour action, which threaten to slow down circulation.
Urban corridors
Urban corridors connect urban spaces into large agglomerated urban regions. In addition to connecting existing cities, it is argued that the infrastructure of urban corridors, once established, promotes urbanisation, and urban growth along the corridor – for example, the Northeast Corridor in the USA, or the Southern Ontario Corridor (Whebell, 1969). Urban corridors are conceptualised either as an agglomeration or as a linear form in planning literature and geographical analysis. Priemus and Zonneveld (2003: 167) identify them as ‘bundles of infrastructure that link two or more urban areas’. Here, connectivity is constituted through multiple branches and nodes to form an agglomeration of urban areas of different sizes connected through different forms of infrastructures, including highways, rail links, air connections, cycle lanes, separate bus lanes and canals (Priemus and Zonneveld, 2003). Other approaches mirror Whebell’s (1969) analysis to focus on the linearity and scale of urban corridors. This body of work argues that urban corridors are linear structures with an urban settlement at either end (Georg et al., 2016; Neuman, 2000; Trip, 2003) and exist on a global scale, sometimes exceeding 1000 km. Such corridors are constituted primarily through high-speed transport infrastructures such as roads and rail (Georg et al., 2016). The form of such a corridor can also be in the form of an arc or loop (Neuman, 2000). UN-Habitat’s (2008) first use of the term urban corridor in 2008 also favours this conceptualisation as a linear spatial form of transportation routes connecting megacities and encompassing their hinterlands.
Urban corridors are usually imagined and found in the context of highly urbanised and densely populated regions, which also enjoy high levels of political integration and stability (Georg et al., 2016). In such cases, the barriers to a fast passage that the corridor model purports to overcome are not political or territorial hostilities but rather technical and institutional fragmentation between transport modes and across governance actors (Priemus and Zonneveld, 2003). Unlike other corridors outlined in this typology, urban corridors centre focus on urbanisation patterns even if underpinned through infrastructure.
Maritime corridors
Maritime corridors are water-based transit corridors focused on trade, suggesting the need for a distinct categorisation while also overlapping and integrating with land-based corridors. Contemporary maritime corridors travel along historical, long-distance oceanic trade routes connecting major ports, port cities and intermediary stopovers to transport freight. Ports act as key land-based nodes and zones of transition in maritime corridors as they need to cater to specific shipping and logistical needs vis-á-vis oceanic passages as well as inland routes and corridors that carry cargo to and from the hinterlands and other cities (Apostolopoulou et al., 2024). Maritime corridors underwent transformation in the post-war period, starting with the shift to air transport for the vast majority of transcontinental passenger traffic as well as much international trade value (Ducruet, 2020). Contemporary maritime corridors, defined as routes or maritime flows produced through the aggregation of vessel movements, have grown considerably less dense as most freight traffic is concentrated along a few major routes centred along deep seaports (Ducruet, 2020). While some scholars explain this rationalisation through the diffusion of containerisation (Guerrero and Rodrigue, 2014), others argue that the overall increase in global trade prompted changes that follow the earlier concentration of maritime flows at deep seaports, which were capable of handling large vessels including bulk carriers (Ducruet, 2020). Increasing centralisation of flows around major hubs, along with the development of better navigational tools since the mid-1990s, has also enabled the formation of large alliances and economies of scale removing redundant ports and routes from networks (Cullinane and Khanna, 2000).
Technological and managerial changes like containerisation, the emergence of global supply chains, just-in-time logistics, the use of extended hinterlands and transnational terminal operators have also changed the governance and functioning of maritime corridors. With a few exceptions, like Antwerp and Hamburg (Notteboom, 2016), upstream ports have declined in usage due to their inability to receive larger vessels, resulting in the shift to the development of the deep-water port at the mouth of an estuary or at other locations along the coast (Ducruet, 2020). As ports become more technologically complex, they have come to rely extensively on knowledge-intensive services and highly skilled labour (Hall and Jacobs, 2012). Port devolution and the emergence of foreign firms and their control over ports have also promoted changes in their operating histories and labour practices (Apostolopoulou, 2021; Brooks and Cullinane, 2006).
Agricultural corridors
Following the recent ‘agricultural turn’ in development planning, agricultural corridors have been promoted as territorial tools for agroindustry development (Chome et al., 2020). Agricultural corridors represent
Agricultural corridors have been cited as a strategy for economic transformation and have been promoted to establish private investments in agriculture aimed towards higher productivity through integration of landscapes into global value chains (Chome et al., 2020; Tups and Dannenberg, 2021). As a model for agricultural economy, these corridors can be analysed in the context of travelling policies and policy discourses, where public–private partnerships for urban and regional development are currently gaining increased interest (Kaarhus, 2011). Gonçalves (2020; see also Chome et al., 2020) examines growth corridors as ‘demonstration fields’ and sites where agricultural projects are celebrated as success stories. They have emerged as a megaproject strategy that combine large-scale logistics construction, such as roads, railways and ports, with commercial agribusiness and investment, proliferating across several actual and policy landscapes (Stein and Kalina, 2019). Studies have also highlighted the potential of agricultural corridors as investment spaces. Wang et al. (2013) note how mineral infrastructure reinforces the dynamics of designated agricultural growth corridors, as well as infrastructure upgrades and agricultural competitiveness, noting its capacity to connect remote hinterland areas with export markets.
Wildlife and conservation corridors
Wildlife corridors are designed towards facilitating the movement of non-human nature with the aim of conserving biodiversity (Hess and Fischer, 2001). These corridors might encompass underpasses, overpasses and culverts along highways that traverse conservation areas (Kusak et al., 2009). They are a high priority in biodiversity and conservation, employed as valuable tools for enhancing the permeability of transportation infrastructure for wildlife while also preventing vehicle collisions and encouraging connectivity (Smith et al., 2015). However, while conservation organisations and agencies recognise the significance of these corridors and advocate for their increased incorporation into conservation plans (Kaya Özdemirel et al., 2016), these are often planned without adequate assessment of potential social and environmental consequences (Hobbs, 2013).
The term ‘wildlife and conservation corridor’ is regularly used in ways that can be contradictory, often without clear and consistent definitions, leading to confusion about objectives and goals (Hess and Fischer, 2001). Simberloff et al. (1992) identified six distinct ways in which the term ‘wildlife corridors’ is utilised, encompassing various scenarios such as habitats aiding movement, greenbelts, buffers in urban areas, biogeographic land bridges, ‘stepping-stone’ refuges for migratory waterfowl, wildlife passages through highway underpasses and tunnels and strips of land facilitating movement between more significant habitats. Additionally, Andrews (1990) emphasises corridors’ role in facilitating the movement of wildlife away from unsuitable sites, enabling local recolonisation of previously extinct areas, aiding species’ movements between different areas required for various life cycle stages and ultimately expanding the overall extent of habitat, particularly for species with extensive range requirements. These ecological functions underscore the roles that corridors play in addressing societal goals, encompassing habitat preservation and facilitating movement as a conduit for circulation (Hess and Fischer, 2001). Given the shortage of information on conservation corridors (Goldman, 2007), their capacity to effectively link landscapes and facilitate the movement of non-human nature remains uncertain. However, this categorisation remains important in thinking through the growing usage of the concept across multiple different spatial planning processes, and through the emphasis on enabling flows of non-human nature vis-á-vis investment in infrastructure.
Illicit corridors
Illicit corridors involve the different uses of zones and other infrastructure to facilitate illicit flows and activities in the global circuits of capital, products and information (Ngo and Hung, 2020), for instance ports, which by existing at the crossroads of security and insecurity are often synonymous with unauthorised flows (Dannenberg et al., 2018). Illicit corridors, due to the fact that they develop parallel to large-scale transport initiatives and may mirror official corridor initiatives, demand analytical attention, which can potentially open up new research pathways when approaching other corridor types. Illicit corridors become spaces where clientelism and corruption can flourish (Dannenberg et al., 2018). Corruption at the governance level enables illicit activities and prevents their detection at various points in the passage of goods and people. For instance, since it is not feasible to check all containers, the potential for illicit trade always manifests due to the always-present possibility of containers carrying weapons, drugs, arms and other toxic products (Basu, 2014). Those with power and control, including brokers of security in port areas, also serve as agents of insecurity around ports (Dannenberg et al., 2018), since such webs of illicit trade are made possible by facilitation and insider assistance. The conflicting interests of the political elite and port stakeholders also create long-term consequences that attract and generate illicit trade at ports. Overall, the making of illicit corridors can displace existing circulation patterns, create new forms of mobility alongside corridor routes and enhance legal and illegal activities, such as small-scale mining, charcoal collection and hunting (Enns, 2018). While global transformations have led to intense surveillance measures, global illicit flows have grown in parallel, with little sign of being curtailed. Activities such as narcotics and arms trafficking as well as money laundering demonstrate that the illicit corridors are often entwined with the official and legally sanctioned corridor, a spatial process that requires further exploration.
Peopled corridors
A corridor may be ‘peopled’ when public, inhabited or occupied. But it may also be peopled if, as a transit corridor, it enables the flow and mobility of people along its channel (Nagai et al., 2006; Newhouse and Simone, 2017). Such corridors are forged through differentiated histories of inhabitation and movement and traversed by many sociocultural practices across various nodes (Toteu et al., 2010).
The term ‘people flow’ has been used to describe movements of people in different environments and at different scales. It has been used in the context of urban planning to describe pedestrian traffic, transit within and between cities (Albrechts and Coppens, 2003), as well as circulation across different geographic regions (Freeman, 2006). Freeman (2006: 145) argues that ‘people flows are fundamental to creating a global economy and that the interplay among immigration, capital and trade is essential to understanding how globalisation affects economies’. Albrechts and Coppens (2003) also note that societies are organised in the ‘spaces of flows’– around flows of capital, people, goods and images. These flows, according to Castells (1996), demonstrate processes dominating our economic, political and symbolic life. For example, migration processes are fuelled not only by the demand of host countries for cheap labour and the dream of a better life but also by the political instability facilitated by the world’s superpowers as the main providers of arms and their role in creating ‘dirty economies’, where formal and informal activities overlap in various shades of grey.
Simone (2004: 407; 2018) introduced the term ‘people as infrastructure’ to argue how those in marginalised, impoverished urban settings construct themselves as infrastructure by engaging with the ‘complexes of objects, spaces, persons, and practices’ in their everyday lives. Conceptually, this notion of ‘people as infrastructure’ opens up new possibilities for existence in cities and extends conceptions of ‘[the] incessantly flexible, mobile, and provisional intersections of residents that operate without clearly delineated notions of how the city is to be inhabited and used’ (Simone, 2004: 407). This perspective allows us to shift our focus to the activities and networks through which communities shape their lives when formal infrastructure is lacking (Addie, 2021: 1350). It therefore invites us to think anew how people create and inhabit them as ‘conduits of force … [which] organize economies, politics, and social life around particular directional priorities’ (Newhouse and Simone, 2017: 4). Migration corridors, for instance, illustrate how people utilise their mobility and circulation to create new possibilities; by providing prospective migrants with information, transportation, initial accommodation and employment, older migrants create the means of navigating and engaging terrain and thus produce new socio-spatial routes that facilitate movement.
Remittance corridors
Remittance corridors, or remittance markets or flows, refer to non-commercial funds transfer systems (Hernández-Coss, 2005) that flow from one country to another as migrant workers or members of diaspora communities send (or receive) money to their ‘home’ countries. Remittance corridors are large, counter-cyclical and pro-poor in comparison to official aid or foreign direct investments. Remittances are often a major source of external financing in many developing countries. Technologies for providing remittance services are changing and moving beyond traditional paper cheques or money orders to electronic transfers and automatic clearing house systems, stored value cards and cell phone-based transfers. Mata-Codesal et al. (2011: 4), in analysing the interface of migration and remittance corridors, read such corridors as ‘a linear system along which flows of people, money, material goods, sociocultural influences, and human relations pass and interact with each other’. They also note that remittance payments sometimes flow in the opposite direction from home to host countries as migrants move back and forth or as extended families transfer funds to support migrants in critical moments (Mata-Codesal et al., 2011).
The diverse range of money transfer methods calls for a more comprehensive breakdown of remittances across various channels. Pieke et al. (2007) highlight that the informal categorisation of remittances is a catch-all category for unaccounted transfers, making it a somewhat misleading classification (see MacIsaac, 2024). Other scholars also argue that the informal/formal divide, and the notion of unidirectional corridors, fail to capture the complexity of these dynamic pathways. For instance, Cirolia et al. (2022) show that money does not flow strictly unidirectionally or linearly but circulates and diverts across urban spaces. They also challenge binary assumptions that formal systems are costly and informal systems are risky, given the overlap between regulatory and risk systems. Additionally, they emphasise how migrants actively shape the infrastructures that facilitate money transfers and remittances and the central role that digital technologies play in shaping these systems, economies and urban spaces in which they operate (Cirolia et al., 2022). While various examples of informal remittance flows have been studied, encompassing cash carried across borders, undisclosed postal goods and other transfer markets and applications such as hawala and hundi (‘transfer’ and ‘trust’), as well as underground banking among African and Asian diasporas (Cirolia et al., 2022; Hernández-Coss, 2005; MacIsaac, 2024; Sithole et al., 2022), the study of informal remittance flows and corridors still lacks much consideration within urban studies.
Conclusion: Critical approaches to corridorisation
Corridors are material and symbolic arrangements of (dis)connectivity which are analytically and socio-technically malleable, fragile and interdependent. Contrary, then, to their strong association with and imaginaries of linear routes embodying and accomplishing one particular function – that of circulating matter across an already delineated passageway between two points – corridors have a rhizomatic quality; they transform space, re-arrange (im)mobility and circulation patterns, are utilised for (bio)political and governance objectives, and re-configure inhabitation practices, as well as playing an important role in either sustaining or harming human and non-human communities alike. In this article, we outlined a genealogy to think through the ways in which this term has been used in different ways across time and space, including its shift from an urban scale to a broader process of rescalarisation to enhance (certain) modes of (dis)connectivity across varied spaces. We offered a loose typology that categorised the varied corridor types in operation and the scholarship that has analysed such initiatives. Returning to Kafka’s conceptualisation of the corridor provides us with a useful lens to acknowledge the messiness, non-linearity, complexity and contradictions embodied by the multiple corridors that have been (re)emerging around the globe, as well as their diverse effects on urban space and the urban political more broadly. As Kafka suggests, corridors are not machines that operate through linearity but rather constellations that expand and extend, opening up new possibilities and closing down others, hence inviting the unexpected and the unanticipated. In our attempt to hold onto this interpretation as we set out to think through this term across urban studies, we outline four broad directions in urban studies scholarship that can be used as analytical lenses through which to navigate the messy enmeshment between the various dynamics of the corridorisation logic and of various corridor types. These are drawn from and synthesise cross-cutting concerns based on our categorisation: planning; politics and social relations; space and territory; and the technological. Given, then, such a heterogeneous assortment of meanings, origins and uses, these four corridor analytics may help grasp the ways in which the multiple, overlapping or even contradictory types, dynamics and meanings of corridors are used in policy and scholarship. They may also suggest new doors to open, passageways to meander in and inquiries to pursue with regard to the socio-spatial dynamics of such arrangements.
Planning
As we have demonstrated, corridors take on various forms and functions in urban-regional, economic and logistical planning. If, as we suggest, corridors are contingent and non-linear, then a strategy to unpick such messiness lies in examining the
Addressing the
Furthermore, within these more totalising discourses and symbolisms, we found that there are competing dynamics and objectives between the urban, infrastructural and development goals of corridors. These processes reflect and reinforce historical dynamics and geo-political representations but also often collide and result in contradictory meanings, goals and objectives pushed and received by a multitude of different interests and actors. This is often visible around the contentious relations between connectivity and economic growth and the politics of equating the two (McCartney, 2022). As Lamarque (2022: 232) aptly underlines, ‘[c]orridors compete not only to be used but also to be funded and built’. Interrogating how the planning of corridors does not correlate to one set of planning objectives but rather proceeds in multiple, often contesting, ways establishes another critical area to investigate.
Politics and social relations
Given the often-massive transformations precipitated through corridors, it is critical to study and assess the myriad of politics and social relations that swirl around these projects. This includes interrogating the
In addition to redoing spatial and political dynamics in the cities, corridors also inform trade, livelihoods and mobility in the communities they traverse as they (re)create interconnectivity between different actors (Brunner, 2013; Grappi, 2018). A large amount of protest and contestation that emerges around corridors is associated with the impossibility of local pastoralists, small businesses and precarious urban communities benefiting from the transnational assemblages of corridors and global capital flows. This can be due to a lack of knowledge, social networks and capital, as well as because of their explicit top-down design. Policy and planning narratives of corridors that emphasise connectivity and friction-free mobilities often obscure how corridors disconnect and interrupt pre-existing flows in multiple ways (Aalders et al., 2021). Intensification of regulation and securitisation, which comes as a result of the establishment of corridors (Karrar, 2022), may come at the expense of marginalised small and medium-sized enterprises and traders since participation is restricted to large corporations (Rippa, 2020). Moreover, while corridors connect political heartlands and urban centres, they isolate transport infrastructure, like roads and highways, from the borderlands and hinterlands that they pass through, disrupting local economies (Rippa, 2020). People’s capacity to anticipate and benefit from changes that corridors enact is based on their socioeconomic standing and ability to adapt to new circuits of capital (Lesutis, 2020).
Corridors are
Space and territory
Several studies have focused on the ways in which corridors produce and inscribe new spatial and territorial boundaries, as well as reshaping older ones (Enns and Bersaglio, 2020; Lesutis, 2020; Thorn et al., 2022). This work highlights how the spatio-material form, dynamic and effect of corridors play a critical role in the ways in which economic, socio-political and technological arrangements play out in the everyday. Corridors allow for and demand thinking about the
These processes may also reflect the violent, harmful effects of corridors; the fact that through imposing and introducing new enclaves and points of everyday friction that reconfigure (im)mobility practices and circulation regimes (Chome et al., 2020; Lesutis, 2020), they can exacerbate social, economic and environmental inequality (Apostolopoulou, 2021; Scholvin, 2021; Zhang and Wen, 2022). Interrogating corridors through the lens of space and territory allows us to understand them as diverse arrangements of
Technological
Corridors can be analysed through the technological and the myriad of systems, standards and operations that constitute them. Across the different corridor typologies, we identified an underlying logic of
The urban-technical also implies paying attention to the ways in which new regimes and modes of
We have used this paper to reflect on what the global pervasiveness of
